The present invention relates to a hinge unit which regulates the angle of rotation, and a hinge structure which uses this hinge unit to support a first box-form body and a second box-form body so that these box-form bodies can rotate relative to each other.
FIGS. 11 and 12 show a hinge unit 100 which is used in a foldable portable telephone. Here, a cylindrical first cam body 104 and second cam body 106 are fit over a shaft 102, so that these cam bodies can rotate relative to the shaft 102.
The first cam body 104 and second cam body 106 have the same shape, and the cam surface 104A of the first cam body 104 and a cam surface 106A of the second cam body 106 contact each other over their entire surfaces in a state that the cam bodies are rotated 90xc2x0 about the shaft 102.
Meanwhile, a flange part 102A is formed on one end of the shaft 102, so that the first cam body 104 is prevented from slipping off. Furthermore, an E-ring 108 is fit over the other end of the shaft 102.
A compression coil spring 110 is mounted between the E-ring 108 and the second cam body 106, so that the second cam body 106 is urged toward the first cam body 104. Accordingly, the second cam body 106 contacts the first cam body 104 or moves away from the first cam body 104 while sliding over the shaft 102 in accordance with the opening angle of the second box-form body 112, thus applying an opening force to the second box-form body 112.
Thus, a tentatively assembled hinge unit 100 is constructed by the shaft 102, first cam body 104, second cam body 106 and compression coil spring 110. However, since various parts of this hinge unit 100 are exposed, the hinge units 100 may become entangled with each other when a plurality of hinge units 100 is packaged and shipped, so that handling is difficult.
In view of the above facts, an object of the present invention is to provide a hinge unit in which there is no entanglement of a plurality of packaged hinge units with each other even if the first box-form body and second box-form body are not attached, so that handling is easy.
Another object of the invention is to provide a hinge unit as stated above, wherein the attachment of the above mentioned hinge unit to the first box-form body and second box-form body is easy.
Further objects and advantages of the invention will be apparent from the following description of the invention.
In a first aspect of the invention, a rotating cam and a slide cam are accommodated in a case, and the rotating cam can rotate relative to the case. Meanwhile, the slide cam is prevented from rotating relative to the case, but can move in the axial direction along the inside wall of the case. Furthermore, the slide cam is urged toward the rotating cam by driving means accommodated in the case.
Here, cam surfaces are formed on the abutting surfaces of the slide cam and rotating cam, and these cam surfaces make contact with each other or move away from each other according to the relative rotational angle of the slide cam and rotating cam, so that the cam surfaces has a contact configuration ranging from a full-surface contact to a partial contact.
Thus, by the movement of the slide cam along the inside wall of the case, even if no shaft is used, the axis does not shift when the slide cam moves. Specifically, since the case is provided with the function of a shaft, an increase in the number of parts of the hinge unit can be prevented.
Furthermore, since the slide cam, rotating cam and driving means are accommodated inside the case, there is no exposure of these various parts. As a result, there is no entanglement of a plurality of packaged hinge units with each other, so that handling is easy.
Furthermore, in this hinge unit, if the case is held and a torque is applied to the rotating cam, the slide cam and rotating cam can be rotated relative to each other. Accordingly, mechanical numerical values, such as the required torque, etc., can be determined. Consequently, torque can be controlled for the hinge unit, so that there is little variation in the product.
Considering a case in which this hinge unit is used, for example, with the case attached to a shaft part on the main body side and the rotating cam connected to a shaft part on the cover side, the rotating cam rotates relative to the case when the cover is opened in the opening direction from a closed state, so that the slide cam moves along the axis of the case in the direction in which the slide cam is separated from the rotating cam by the action of the cam surfaces, thus causing the contact configuration of the cam surfaces to reach a partial contact.
When the cover is further opened from this stage, the cam surface of the rotating cam rides over the peak parts of the cam surface of the slide cam, so that the slide cam is caused to move toward the rotating cam by the driving force of the driving means. This moving force is converted by the cam surfaces into a force that rotates the cover via the rotating cam.
In a second aspect of the invention, the slide cam contacts inside the case. As a result, shifting of the axis of the slide cam is prevented even more securely.
In a third aspect of the invention, a connecting part is formed on the rotating cam, and this connecting part protrudes to the outside from the box-form case. By thus causing a connecting part to protrude from the case, it is possible to apply torque to the rotating cam without any particular need to screw a connecting tool, etc., into the rotating cam.
Meanwhile, a square guide plate is molded as an integral part of the slide cam, and this guide plate can slide along the inside wall of the case. By thus forming the case in a box shape and forming the square guide plate on the slide cam, it is possible to prevent rotation of the slide cam by means of a simple structure.
In a fourth aspect of the invention, the connecting part is formed in the shape of a square column. Accordingly, since the connecting part is prevented from rotating with respect to the accommodating part merely by forming the accommodating part with an angular shape, there is no need to use a complex shape as in conventional device, so that working costs can be reduced.
In a fifth aspect of the invention, the diameter of the circumferential wall of the aforementioned slide cam is the same as the width of the aforementioned guide plate. Accordingly, not only the side surfaces of the guide plate, but also the circumferential wall surfaces of the slide cam, slide along the inside wall of the case, so that the sliding contact area with the inside wall of the case is increased. Consequently, the slide cam can move without any shift in the axis of the slide cam.
In a sixth aspect of the invention, the aforementioned cam surface of the slide cam includes peak parts and valley parts, and the peak parts and valley parts are disposed at 90-degree intervals. Furthermore, the corner parts of the aforementioned guide plate are positioned in the vicinity of straight lines that connect the axial center of the slide cam with the valley parts as seen in a plan view.
Since the parts that slide along the inside wall of the case are the circumferential wall of the slide cam and the side surfaces of the guide plate, the contact area of the inside wall of the case relative to the circumferential wall of the slide cam and side surfaces of the guide plate can be large in order to prevent any shift in the axis of the slide cam.
Accordingly, in case where the side surfaces of the guide plate are positioned in the vicinity of the straight line that connects the axis of the slide cam and the valley parts of the cam surface, the valley parts and peak parts of the cam surface are positioned substantially at the centers of the side surfaces of the guide plate.
In this case, the length that slides along the inside wall of the case at the approximate centers of the side surfaces of the guide plate becomes equal to the thickness of the guide plate on the sides of the valley parts of the cam surface. Meanwhile, on the side of the peak part of the cam surface, the length that slides along the inside wall of the case is a length produced by adding the height of the peak part to the thickness of the guide plate.
Since the length that slides along the inside wall of the case at the approximate center of the side surface of the guide plate varies between the peak part side and valley part side, the contact area between the inside wall of the case and the circumferential wall of the slide cam and side surfaces of the guide plate varies, so that there is a danger that the axis may shift in some cases where the slide cam moves.
However, in case the corner parts of the guide plate are disposed in the vicinity of the straight line that connects the axis of the slide cam with the valley parts as seen in a plan view, the lengths that slide along the inside wall of the case at the approximately centers of the side surfaces of the guide plate are all the same.
As a result, the contact area between the inside wall of the case and the circumferential wall of the slide cam and side surfaces of the guide plate remains more or less the same. consequently, the slide cam moves more stably, so that there is no danger that the axis of the slide cam will shift.
In a seventh aspect of the invention, closing parts extend from the case, and are bent so that these closing parts prevent the slide cam from ejection of the case. Thus, since the slide cam can be prevented from ejection merely by bending these closing parts, the working characteristics are good.
In an eighth aspect of the invention, cut-out parts are formed at the base parts of the closing parts, and these cut-out parts determine the bending positions when the closing parts are bent. Thus, the bending of the closing parts is facilitated by the formation of cut-out parts at the base parts of the closing parts. Furthermore, since the bending positions are determined by the cut-out parts, protrusion of the bending position from the plane of the peripheral edge parts of the case can be prevented..
In a ninth aspect of the invention, a plurality of driving means is used. As a result, since the area contacting the slide cam is increased as compared to a case in which a single driving means is used, the slide cam can move smoothly with a good balance. Furthermore, as a result of the use of a plurality of driving means, fine adjustment of the driving force is possible.
In a tenth aspect of the invention, the rotating cam is connected to a shaft part installed in a first box-form body, the case is fastened to a shaft part installed in a second box-form body, and the first box-form body and second box-form body can rotate relative to each other.